CaSTaway/GP is a brand new Atari ST emulator for the GP32. As the version title says its an alpha release so expect bugs, crashes etc. Heres some notes from the author:

This release is still totally unusable, but it does look pretty (see the screenshot). Mouse can only go right/down, its very slow to load and run and render. But it *works*, and thats something. I imagine it coudl be sped up quite a lot, but I’m not sure if it would ever be usable on the GP32. But I’ll try 🙂

Visit his homepageherefor more information and the downloads.